This application relates to a carpet pad and system for holding a carpet in place without stretching. The system is of the general type illustrated and described in U.S. Pat. No. 4,557,774, issued Dec. 10, 1985 to the same inventor and assignee as this application.
The system of the present invention involves a carpet cushion which has a pressure sensitive adhesive preapplied to one surface of the cushion or padding, as opposed to U.S. Pat. No. 4,557,774, which disclosed pressure sensitive adhesives preapplied to both surfaces. U.S. Pat. No. 4,557,774 is hereby incorporated in this disclosure by reference.
The present invention also relates to carpet pads or cushions having a hot melt pressure sensitive adhesive applied to an otherwise uncoated and unsealed porous padding surface which would be unsuitable for a water based pressure sensitive adhesive. On such porous surfaces, water based adhesives tend to wick excessively into unsealed porous surfaces.
Conventionally, carpeting has been installed on floors in several different ways. In the conventional tackless strip system, the so-called tackless strip is secured to the floor around the walls of the room, the carpet is hooked onto the upwardly protruding nails of the tackless strip at one side of the room, and the carpet is stretched before it is hooked to the tackless strip at the opposite side of the room. One problem with this system is that it requires the installation of the tackless strip, which is time-consuming and which is difficult when concrete floors are encountered. Another problem is that it requires a trained professional to re-stretch the carpet in the event a corner or edge portion of the carpet needs to be temporarily taken up, access to the floor or for drying a carpet which has been wetted.
Many carpet installations involve gluing of the carpeting to the floor, without any carpet cushion or pad between the carpet and the floor. With such an installation, the carpeting can be of less expensive construction, with a primary backing but without the need for a secondary backing (jute or polypropylene backing) which is generally required for stretched carpeting. The glued down carpeting avoids wrinkling without the need for stretching, but loses the benefit of a carpet pad. Also, the carpet can be very difficult to remove either for replacement or temporarily, for maintenance, without destroying the floor or the carpeting itself due to the adhesion of the glue.
In glue-down installations, the carpet is ordinarily laid on the floor first and seamed as required. The glue is then applied to the floor, either in liquid form or by spraying it onto the floor. This can be accomplished by folding back half of the carpet, applying the glue to the floor in that area, and dropping the carpet in place to adhere it to the floor in that area. The opposite side of the carpet could then be folded back, glue applied to the floor in that area, and that portion of the carpet then adhered to the floor.
Another installation system wherein the carpet was adhered to the floor without padding is disclosed in U.S. Pat. No. 4,405,668 to Wald. This system used a separate, thin scrim web with adhesive on both sides and with a release film on one side. The scrim web was placed on a floor with the release film on the upper surface, adhering the web to the floor, whereupon the carpet could then be seamed and cut as required while lying on top of the release film. The carpet was then folded back and the release film removed in one area, that portion of the carpet was pressed down, and the operation was repeated in another area. This system was relatively expensive and still did not permit the installation of a carpet pad beneath the carpeting. A similar construction of adhesive webbing material is shown in U.S. Pat. No. 4,234,649 to Ward.
In yet another system for installing carpet without stretching, a slab or pad of jute material was interposed between the carpet backing and the floor. In this particular system the floor was sprayed with a wet adhesive, the slab of jute material was laid into the adhesive while the adhesive was still wet, the top surface of the jute material was sprayed with the wet adhesive, and the carpet was laid on the wet adhesive on the top surface of the jute slab or pad. The wet adhesive, as it dried, became enough of a pressure sensitive adhesive to permit the carpet to be pulled up and removed.
This system had the disadvantage of being an expensive system because of the costs required to make an on-the-job installation.
As noted above, U.S. Pat. No. 4,557,774 illustrates and discloses a carpet cushion and carpet-laying system similar to some aspects of the present invention, the principal difference being that in some embodiments of the present invention the cushion has a pressure-sensitive adhesive preapplied to only one surface.
Water based pressure sensitive adhesives when applied to a carpet cushion are liquid, and will wick excessively into any porous surface such as the porous surface of an untreated felt pad or rebonded urethane pad or of a porous remay which has often been used over a carpet cushion surface. Consequently, some type of surface sealing is required for the use of such adhesives, examples being a thin plastic skin adhered to the porous surface, or a sprayed-on sealant, or a crust formed at the surface to seal the pad, as by heating. The need for such sealing is avoided in one aspect of the present invention described below.